LSH for a wordlist

Question

I am trying to write a spellchecker, I have a huge wordlist (at least 500K, because of the nature of the language). The performance would suffer a lot if I got the lavenshtein distance of all of the words in the wordlist to the current word.

So I am trying to distribute the wordlist into buckets based on the characters in the word. This way, I only need to get the Levenshtein distance of the words in the specific bucket instead of the whole wordlist.

So I was wondering if there are any good Locality Sensitive hash algorithms for my problem? I have written a very simple algorithm that seems to work okay and the performance is at least 20X better. Although the accuracy suffers quite a bit.

Here is what I have come up with:

static string GetHash(string word)
{
    word = word.ToUpperInvariant();
    var lettersToTake = word.Length - (int)(word.Length * 0.70);

    var chars = word.GroupBy(c => c)
                    .OrderByDescending(c => c.Count())
                    .ThenBy(c => GetFrequency(c.Key))
                    .Take(lettersToTake)
                    .Select(g => g.Key)
                    .ToList();

    return new string(chars.ToArray());
}

Here are the steps of the algorithm:

1. Capitalize all of the characters
2. Order the characters in the word by the frequency of the letter in the word
3. Then order the characters by the frequency of the word in the entire wordlist (GetFrequency)
4. Take 30% of the characters in the word